The present invention relates to a base station apparatus for use in mobile communications systems.
A technique for providing a mobile cellular communication system capable of eliminating communication failure states otherwise occurring due to temporal congestion is disclosed in JP-A-10-66138. This mobile communication system is such that a plurality of network-linkable fixed base stations communicate via radio channels with mobile phones existing in coverage areas of the fixed base stations, wherein the mobile communication system includes a first detector unit for detecting from among the plurality of fixed base stations a first fixed base station which presently experiences occurrence of congestion, a mobile base station which is movable in the air for setup of a radio channel that is free from interference or cross-talk with the radio channel being presently used by the first fixed base station and for performing communication with a mobile phone existing in an area of the first fixed base station by way of the interference-free radio channel, and a control device for controlling the movement or “migration” of the movable base station based on a detection result of the first fixed base station. More specifically, let the movable base station move to the area having convergence problems for setting up a radio channel at which the convergence does not occur and for permitting communication between the movable base station and the mobile phone, thereby achieving the objective that avoids communication failure state due to temporal congestion. Additionally, depending on circumstances, the same object is achieved by causing the movable base station to operate as a repeater of a fixed base station having many out-of-use or “vacant” channels, also known as available channels.